It has heretofore been suggested that two flexible tubes can be brought together to form a dual flexible tube package, as shown for example, in U.S. Pat. No. 3,782,600, 4,687,663, 5,052,590, 5,244,120, 5,269,441, and 5,318,203.
In U.S. Pat. No. 5,318,203, there is disclosed the concept of utilizing elongated hollow flexible tubes, each of which has an upper end and lower end wherein the upper end is D-shaped and the lower end is round or oval shaped. The upper ends of the tubes are attached to a coupling which is joined to a dispensing base. The coupling has two exit orifices, one for each tube. The dispensing base includes two nozzles which are inserted into the two orifices.
Among the objectives of the present invention are to provide a dual flexible tube package which will effectively segregate active ingredients in the respective tubes; which is more readily manufactured; which is more readily filled; and which is more readily sealed.
In accordance with the invention the dual chamber flexible tube dispensing package comprises two substantially identical tubes that are mirror images of one another, except for the finishes. Each tube includes a rigid half finish, a rigid half shoulder and a flexible tubular body extending from the shoulder. The cross sections of the half finish, half shoulder and body of each tube are D-shaped such that each has a flat portion and all the flat portions are in a single plane. The two tubes have the flat portions in abutting relation to one another such that the dual tube package has a finish defined by the two half finishes, a shoulder defined by the two half shoulders and a dual chamber body defined by the two flexible tube bodies. The threads on the half finishes are located thereon such that when the two tubes are brought into abutting relation a continuous thread is formed on the finish. The resultant dual chamber flexible tube packages are then filled with the respective viscous materials and the open ends are sealed to complete the package. In another form of dual chamber dispensing package, each tube has a plurality of vertically spaced integral ribs which extend transversely. The ribs on one tube are staggered relative to the ribs on the other tube so that when the tubes are brought into engagement, the ribs on one tube engage the ribs on the other tube and the first portions of the shoulders are in abutment. Each rib is convex outwardly when viewed in transverse cross section.
The dual chamber flexible tube dispensing packages are formed by providing a pair of plastic parisons, blow molding each parison to form a container having a rigid half finish, a rigid half shoulder adjacent the finish and a flexible body extending from the shoulder to a rigid closed lower end. The rigid closed end of each container is cut-off to produce the two tubes. The flat portions of the two tubes are then brought into abutting relationship such that when the flat walls of the two tubes are in abutting relation, the thread on the half finish on one tube forms a continuous thread with the thread of the half finish on the other tube. This results in the dual chamber flexible tube dispensing package. The overall cross section of the resultant finish is cylindrical. The overall cross sectional configurations of the shoulder and flexible body are generally oval or round with the major axis at ninety degrees to the abutting flat portions.